/*
 * Copyright 2011 Clean GWT
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.cleangwt.bootstrap.support.client;

import java.util.HashMap;
import java.util.Map;

import com.cleangwt.bootstrap.client.style.Forms;
import com.cleangwt.validation.client.DefaultErrorHandler;
import com.cleangwt.validation.client.ValidationErrorHandler;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.ui.Widget;

/**
 * A {@link ValidationErrorHandler} to prompt error message with an label.
 * 
 * @author Jess
 * @version 1.0
 * @since 1.0
 */
public class LabeledErrorHandler extends DefaultErrorHandler {

  private Map<Widget, Element> errorElements = new HashMap<Widget, Element>();

  @Override
  public void resetCompoentError(Widget component) {
    super.resetCompoentError(component);
    removeErrorLabel(component);
  }

  @Override
  public void setComponentError(Widget component, String errorMessage) {
    super.setComponentError(component, errorMessage);
    appendErrorElemet(component, errorMessage);
  }

  private void appendErrorElemet(Widget component, String errorMessage) {
    Element e = errorElements.get(component);
    if (e == null) {
      e = Document.get().createLabelElement();
      e.setClassName(Forms.CONTROL_LABEL_STYLE);
      errorElements.put(component, e);
    }
    e.setInnerHTML(errorMessage);

    component.getElement().getParentElement().insertAfter(e, component.getElement());
  }

  private void removeErrorLabel(Widget component) {
    if (errorElements.containsKey(component)) {
      component.getElement().getParentElement().removeChild(errorElements.remove(component));
    }
  }
}
